Revision and phylogeny of the genus Loxoneptera Hampson, 1896 (Lepidoptera, Crambidae, Pyraustinae), based on morphology and molecular data

Abstract The genus Loxoneptera Hampson, 1896 is revised based on external appearance and genitalia. It is comprised of eleven species, of which three are described as new species from China: L. crassiuncata Chen & Zhang, sp. nov., L. triangularis Chen & Zhang, sp. nov., and L. rectacerosa Chen & Zhang, sp. nov.; six species are proposed as new combinations: L. carnealis (Swinhoe, 1895), comb. nov., L. medialis (Caradja, 1925), comb. nov., L. pentasaris (Meyrick, 1932), comb. nov., L. bipunctalis (Hampson, 1912), comb. nov., L. brevipalpis (Snellen, 1890), comb. nov., and L. dichroma (Moore, 1888), comb. nov. A new replacement name, L. hampsoni Chen & Zhang, nom. nov., is proposed for L. carnealis Hampson, 1896, the type species of the genus, because it is a secondary homonym of L. carnealis (Swinhoe, 1895), comb. nov. External characters and genitalia morphology of all species are figured. Nucleotide sequences of COI, 16S rRNA, 28S rRNA, and EF-1α were used for the molecular analysis and phylogeny of Loxoneptera species.


Introduction
The genus Loxoneptera was established as a monotypic genus by Hampson (1896), based on L. carnealis Hampson, 1896 from Sikkim and Assam. Subsequently, Swinhoe (1906) described a new species, L. albicostalis, from Padang, Sumatra, mainly based on appearance of the wings. The genus was not investigated again until Chen et al. (2018) who, for the first time, recorded these two species in China (see also Nuss et al. 2003Nuss et al. -2021. They noted that Loxoneptera was paraphyletic, with respect to two species of Calamochrous Lederer, 1863, i.e., C. carnealis (Swinhoe, 1895) and C. medialis Caradja, 1925, appeared as terminal lineages within Loxoneptera clade based on a molecular phylogenetic analysis. But C. carnealis and C. medialis were not transferred to Loxoneptera in their study.
Within the additional Chinese specimens collected, three undescribed species of Loxoneptera were recognised. Moreover, a few species of Calamochrous and Anania Hübner, 1823 were found to be congeneric with species of Loxoneptera. The aim of this study is to diagnose Loxoneptera based on external and genital characters, to clarify the species included in the genus, and to provide a preliminary phylogenetic hypothesis based on selected genetic markers.

Materials and methods
The material studied, including the types of the newly described species, are all deposited at the Museum of Biology, Sun Yat-sen University, China (SYSBM) except those stored in the following institutions: Insect Collection of the College of Life Sciences, Nankai University, China (NKU), Forest Canopy Ecology Lab, Yunnan, China (FCEL), "Grigore Antipa" National Museum of Natural History, Romania (MGAB), and Natural History Museum, London, United Kingdom (NHMUK). Slides of genitalic dissections were prepared according to Robinson (1976) and Li and Zheng (1996), with some modifications. Genitalia terminology follow Klots (1970), Munroe (1976), Maes (1995), and Kristensen (2003). Images of the adults were taken using a Canon EOS 60D camera provided with a Canon 100 mm macro lens; the genitalia images were taken using Zeiss Axio Scope.A1 in combination with a Zeiss AxioCam camera and the Axio Vision SE64 program on a Windows PC; source images were then aligned and stacked on Helicon Focus to obtain a fully sharpened composite image. All images were edited using Adobe Photoshop SC5.
Ten species in four genera were included in the molecular phylogenetic analyses (Table 1). Euclasta stoetzneri (Caradja, 1927) was chosen as the outgroup because it has been inferred as sister-group of Pyraustini and Portnetomorphini in Pyraustinae (Mally et al. 2019). One species of Sclerocona Meyrick, 1890 and three species of Eumorphobotys Munroe & Mutuura, 1969 were also included as related genera to Loxoneptera according to Chen et al. (2018). Total DNA was extracted from two legs, and sometimes from the abdomen of the dry specimens using the TIANGEN DNA extraction kit following the manufacturer's instructions. The nucleotide sequences of two mitochondrial genes, cytochrome c oxidase subunit I (COI) and 16S ribosomal RNA (16S rRNA), and two nuclear genes, 28S ribosomal RNA (28S rRNA) and Elongation factor-1 alpha (EF-1α) were selected for study. Primers used in this study and all PCRs performed are the same as in Zhang et al. (2020). PCR products were confirmed with 1.5% agarose gel electrophoresis in TAE buffer, then were purified and directsequenced at Majorbio Bio-pharm Technology Co., Ltd (Guangzhou), utilising the same primers used for PCR amplification. The sequences were aligned using Clustal W (Thompson et al. 1994) in MEGA 6 (Tamura et al. 2013) with default settings. The aligned matrix was corrected by eye. Gaps were treated as missing data. Phylogenetic analyses were inferred using Bayesian inference (BI) method in MrBayes 3.2.6 (Ronquist et al. 2012) and maximum likelihood (ML) in RAxML 8.2.10 (Stamatakis 2014). BI analysis was run with independent parameters for the COI, the 16S rRNA and 28S rRNA gene partitions under the GTR + G model, the EF-1α gene partition under the GTR + G + I model, as suggested by jModelTest 0.1.1 (Posada 2008). Two independent runs, each with four Markov Chain Monte Carlo (MCMC) simulations, were performed for 20 million generations sampled every 1000 th generation. The first 25% trees were discarded as burn-in, and posterior probabilities (PP) were determined from remaining trees. ML analysis was executed under the GTR + G model for all gene partitions and with 1000 iterations for the bootstrap test. The pairwise Kimura 2-Parameter (K2P) distances between species were calculated from the COI gene using MEGA 6 (Tamura et al. 2013).

Phylogenetic relationships
The concatenated dataset of four genes consisted of 2511 nucleotide positions (658 for COI, 463 for 16S rRNA, 619 for 28S rRNA, and 771 for EF-1α). Both BI and ML analyses of the concatenated dataset inferred congruent topologies with only subtle differences in posterior probability and bootstrap values probability (Fig. 1). The monophyly of Loxoneptera is strongly supported in BI but weakly supported in ML (PP = 0.93, BS = 65). Eumorphobotys is in a sister group position to Loxoneptera with robust support (PP = 1.00, BS = 100).

Diagnosis.
In external appearance, the species of Loxoneptera are similar to species of Eumorphobotys Munroe & Mutuura, 1969 in the long and porrect labial palpus, the usually concolorous wings with no obvious pattern and the straight termen of forewing, but can be best distinguished by the triangular uncus, the rod-shaped dorsal projection of transtilla bearing long and thick hair at the apex, and the hookshaped ventral sella in the male genitalia. In the female genitalia, the ductus bursae of Loxoneptera is shorter and stouter than that of Eumorphobotys. These two genera are also different in the shape of the signum, if present a nearly rhomboid signum with connected carina, or reduced into a keel-like carina in Loxoneptera, and a nar- rowly rhomboid signum with carina interrupted in Eumorphobotys. Eighth sternite in males of Loxoneptera is slightly sclerotised, with two slender and sclerotised anterolateral processes. Description. Head. Frons oblique, slightly protruding. Vertex with moderately raised scales projecting between antennae. Labial palpus ~ 2-2.5 × eye diameter; second segment obliquely upward, third segment long and porrect. Maxillary palpus small. Thorax. Legs unmodified usually, outer spur 1/3 to 1/2 the length of inner spur, sometimes outer spur minute. Wings. Forewing elongated triangular, termen obliquely straight to slightly curved; discal cell ~ 1/2 length of wing, R 1 from ~ 3/4 of anterior margin of cell, R 3 and R 4 stalked to more than half of R 4 , R 5 free from anterior angle of cell, parallel to stalked R 3 +R 4 at base, then diverging, discocellular veins concavely curved, M 1 close to R 5 at base, free from discocellular veins and close to anterior angle of cell, M 2 , M 3 and CuA 1 from posterior angle of cell, CuA 2 from 4/5 of the posterior margin of cell, 1A faintly sinuate to tornus; 2A forming complete loop and distally recurved before joining 1A; usually only with orbicular and reniform stigmata, sometimes no pattern. Hindwing fan-shaped, termen rounded; discal cell less than half length of wing, Sc+R 1 and Rs anastomosed to half of Rs, discocellulars concave, M 2 , M 3 and CuA 1 from posterior angle of discal cell, CuA 2 from 4/5 of the posterior margin of cell; without obviously spot. Abdomen. Eighth sternite in male with two slender and sclerotised anterolateral processes, pointed or slightly stout (Fig. 14).
Male genitalia. Uncus triangular, glabrous or with few hair-like setae. Tegumen trapezoid. Saccus nearly triangular. Transtilla with developed ventral process, extending a rod-shaped projection dorsad, usually long, curved, and slender, and terminal part with many long hairs. Valva tongue-shaped; dorsal sella membranous, ventral sella Table 2. Pairwise distance of the COI barcoding region based on Kimura-2-parameter model. usually with a hook-shaped, strongly sclerotised process, dorso-distal sella presented as a sclerite and usually extended as a long, hook-shaped, sclerotised process; editum absent or not obvious; sacculus broad. Juxta with basal part rivet-shaped, remainder usually with two long and slender bifid arms. Phallus tubular, vesica with spine-shaped cornuti and sometimes deciduous cornuti. Female genitalia. Ovipositor lobes flat, densely setose. Anterior apophyses longer than posterior apophyses. Antrum sclerotised, cup-shaped or bowl-shaped; colliculum well developed and sclerotised; ductus seminalis entering near anterior end of colliculum; ductus bursae short and stout, almost as long as length of corpus bursae; corpus bursae oval, appendix bursae oval or absent, signum nearly rhomboid, with a carina not interrupted in middle, sometimes signum reduced into a carina, sometimes absent.
Distribution. China, India, Indonesia, Malaysia. Costal band of forewing white, fringe white and with basal 1/4 black-brown (Fig. 4), a small triangular indentation presented on the 1/3 of posterior margin in male; ventral sella with a long hook-shaped process; vesica without cornutus ( Distal part of phallus with a long and pointed spine, longer than the length of phallus (Fig. 18)  Distal part of juxta with a strongly sclerotised and narrowly triangular process (Fig. 19)  Distal end of phallus densely decorated with short spines (Fig. 22)  Forewing with a stripe along posterior margin of cell (Fig. 13); ventral-distal wall of phallus weakly sclerotised and obliquely extended into a process (Fig. 25)  Diagnosis. Loxoneptera hampsoni is easily distinguished from other Loxoneptera species as follows: forewing with distinct, black-brown and point-like orbicular and reniform stigmata, bearing pale yellow stripes between veins, and veins with ochrebrown scales forming streaks; dorsal sella with a long and slender rod-shaped extension in the male genitalia.

Key to species of Loxoneptera
Redescription. Head. Frons brown, with white lateral bands. Vertex brown, mixed with some white erected scales. Labial palpus dark brown, with white scales on ventral side. Maxillary palpus brown. Antennae brown. Thorax. Dorsal side, patagia and tegula yellowish brown, ventral side grey white. Foreleg yellowish brown, dorsal tarsus grey white; ventral femur and tibia of midleg and hindleg grey white, others pale yellow. Wings. Wingspan 29.0-36.0 mm. Forewing termen straight, a small triangular indentation presented on 1/3 of posterior margin in male, and with a group of black-brown scales; yellowish brown, mixed with ochre-brown scales, pale yellow stripes presented between veins, and veins covered with ochre-brown scales forming streaks; orbicular stigma appearing as a black point, reniform stigma black, small and round; fringe white, basal 1/5 black-brown. Hindwing in male black-brown on terminal area, remaining areas pale yellow, a triangular patch present near posterior angle of cell, slightly concave and densely covered with pale brown scales; in female pale yellow, mixed with ochre-brown scales on termen; fringe brown in male, pale yellow in female. Abdomen. Dorsal side of abdomen black-brown, ventral side grey white; 5 th abdominal segment with a group of pale yellow scales on each side in male; sternite VIII in male slightly sclerotised with two pointed anterolateral processes.
Male genitalia (Fig. 15). Uncus somewhat wide and short, distally narrowly rounded, without setae. Saccus narrow. Dorsal projection of transtilla relatively thick and slightly curved, ~ 1/2 length of costa, distally bearing hair almost as long as projection. Valva with dorsal margin slightly concave, ventral margin nearly paralleled with dorsal margin, apex truncate; costa wide; dorsal sella membranous, rod-shaped, rather slender, and fragile; ventral sella sclerotised, with a somewhat straight, hook-shaped process; dorso-distal sella with a pointed process extended beyond ventral margin of valva; sacculus broad. Juxta heart-shaped, middle part concave inwardly, with wide arms. Phallus with vesica bearing two groups of spine-shaped cornuti, one longer and curved, another short and straight.
Female genitalia (Fig. 26). Anterior apophyses 1.5 × as long as posterior apophyses. Lamella postvaginalis with weakly sclerotised transversely wrinkles, with dense and tiny spines; lamella antevaginalis with two curved and sclerotised notches. Antrum weakly sclerotised, cup-shaped, width 3 × as long as length; colliculum well developed and heavily sclerotised, expanded in middle part, length of colliculum ~ 1/3 of ductus bursae; ductus bursae slightly longer than length of corpus bursae; corpus bursae oval, appendix bursae arising from lateral side, small; signum broadly rhomboid, maximal length less than half width of corpus bursae, carina well-developed, laterally bearing with dense tiny spines, other two arms short and stout.
Distribution. China (Hainan, Yunnan, Tibet), India. Etymology. The species is renamed after the last name of George Hampson, who proposed the genus Loxoneptera in 1896.
Remarks. According to the characters of the male and female genitalia, Calamochrous carnealis (Swinhoe, 1895) is transferred to Loxoneptera in this paper, which creates a secondary homonym of Loxoneptera carnealis Hampson, 1896, the type species of Loxoneptera. The specific name of Loxoneptera carnealis Hampson, 1896 is not valid, therefore we give it a new replacement name, i.e., Loxoneptera hampsoni nom. nov. Swinhoe, 1906 Figs 4, 14, 16 Loxoneptera albicostalis Swinhoe, 1906 Diagnosis. In appearance, Loxoneptera albicostalis is extremely similar to L. crassiuncata and Eumorphobotys horakae Chen & Zhang, 2018 in the wing shape, the clean reddish brown forewing and the dark brown hindwing, but can be distinguished by the whiter costa of both wings, a group of dark brown scales on the posterior margin of forewing, and a group of scales on each side of the 5 th abdominal segment in male. The underside of forewing in L. albicostalis is smoky brown, while that of E. horakae is pale yellow from anterior margin of cell to posterior margin. The male genitalia resemble that of L. crassiuncata but can be differentiated by the shorter and stouter uncus, the relatively longer and slender dorsal projection of transtilla, nearly triangular dorsal sella, the long and hook-shaped process of the ventral sella, as well as the absence of the spine-shaped cornutus in phallus.

Loxoneptera albicostalis
Redescription. Head. Frons brown. Vertex brown, mixed with some yellow erected scales. Labial palpus dark brown, with white scales on ventral side. Maxillary palpus brown. Antennae yellowish brown. Thorax. Dorsal side, patagia and tegula brown, ventral side grey white. Legs pale yellow to grey white; hindleg basal outer spur 1/5 of basal inner spur. Wings. Wingspan 32.0-36.0 mm. Forewing wide, reddish brown, without pattern; costal area white, mixed with pale brown scales at apex; termen straight; a small triangular indentation presented on the 1/3 of posterior margin in male, and with a group of black-brown scales; fringe white, with basal 1/4 black-brown. Hindwing black-brown, costa area pale yellow; a triangular patch presented near the posterior angle of cell, densely covered with pale brown scales; fringe black-brown. Underside smoky dark brown on forewing, and pale brown on posterior margin area. Abdomen. Dorsal side black-brown, ventral side grey white; abdominal segment V with a group of dark scales on each side in male; sternite VIII in male slightly sclerotised with two pointed anterolateral processes.
Remarks. The forewing colour of the type material of Loxoneptera albicostalis is pale yellow tinged with some reddish brown scales and differs from the specimen collected in China. No obvious difference could be found in the male genitalia between the type specimen and the Chinese specimen. Diagnosis. Loxoneptera crassiuncata is similar to L. albicostalis in reddish brown forewing colour but male specimens can be distinguished by the unbroken posterior margin of forewing (without a small triangular indentation), without a group of blackbrown scales, and abdominal segment V without a group of dark scales. In the male genitalia, it can be differentiated by the longer and slender uncus, the shorter and stouter dorsal projection of transtilla, the slender and rod-shaped dorsal sella, the relatively shorter and slightly curved process of the ventral sella, as well as the presence of a horn-shaped cornutus in phallus.
Description. Head. Frons brown. Vertex brown. Labial palpus brown, with white scales on ventral side. Maxillary palpus brown, broadened distally with scales. Antennae dark brown. Thorax. Dorsal side, patagia and tegula brown, ventral side grey white. Legs yellowish white or pale yellow, dorsal of midlegs and hindlegs yellowish brown; hindleg with basal outer spur 1/4 of inner spur. Wings. Wingspan 29.0-31.0 mm. Forewing wide, termen nearly straight; reddish brown, brown at basal half of posterior portion, costal band brown, without pattern; fringe pale yellow, basal half and the posterior angle black-brown. Underside greyish brown. Hindwing black-brown, pale yellow on anterior margin; a triangular patch presented near the posterior angle of cell, the margin of triangular patch with pale yellow scales and the outer margin dentate; fringe black-brown. Underside greyish brown. Abdomen. Dorsal side of abdomen brown, ventral side pale yellow; sternite VIII in male slightly sclerotised with two pointed anterolateral processes.
Male genitalia (Fig. 17). Uncus slightly narrow, distally narrowly rounded, with several setae. Saccus narrow. Dorsal projection of transtilla rather thick and straight, ~ 1/4 length of costa, distally bearing setae ~ 2 × length of projection. Valva with dorsal margin slightly concave, ventral margin nearly parallel with dorsal margin, and apex slightly truncate; costa narrow; dorsal sella membranous, long and slender, rod-shaped and fragile; ventral sella with a stick-like and strongly sclerotised process; dorso-distal sella with a short stick-like process, pointed apically; sacculus broad, extended dorsad with a triangular protrusion in the middle. Juxta with basal part narrow, two arms rather broad. Phallus stout, vesica with a horn-shaped and strongly sclerotised cornutus apically.

Distribution. China (Yunnan).
Etymology. The specific name is derived from the Latin crassi-(thick) and uncatus (horn-shaped), referring to the shape of cornuti in the phallus. (Swinhoe, 1895) Diagnosis. This species is similar to Loxoneptera triangularis in appearance, but can be distinguished by the following characters: forewing mixed with reddish brown scales, a distinct dark brown stripe appearing near posterior angle of cell; apex of hindwing with a dark brown patch; dorso-distal sella with a hook-shaped process; distal end of phallus with a spine-shaped process, longer than phallus length.

Loxoneptera carnealis
Redescription. Head. Frons pale reddish brown, with white lateral bands. Vertex pale brown, mixed with some reddish brown erect scales. Labial palpus reddish brown, with white scales on ventral side. Maxillary palpus reddish brown, broadened distally with scales. Antennae yellowish brown. Thorax. Dorsal patagia and tegula ochrebrown, ventral side grey-white. Legs pale yellow to grey-white; hindleg basal outer spur 2/5 of basal inner spur. Wings. Wingspan 22.0-29.0 mm. Forewing yellowish brown, densely mixed with reddish brown scales; dark brown from costal margin to posterior margin of cell; costal margin white; orbicular stigma appearing as a black-brown point, reniform stigma black, appearing as a thick streak on discocellulars; a distinct dark brown stripe appearing near posterior angle of cell; fringe black-brown. Hindwing pale yellow, apex with a dark brown patch; fringe pale yellow. Underside of forewing pale yellow, black-brown from costal margin to posterior margin of cell. Abdomen. Dorsal side of abdomen black-brown, ventral side grey white; sternite VIII in male slightly sclerotised with two pointed anterolateral processes.
Male genitalia (Fig. 18). Uncus long, triangular, distally narrowly rounded, with few hair-like setae. Saccus rounded. Dorsal projection of transtilla relatively slender and slightly curved, ~ 3/4 length of costa, distally bearing hair ~ 1/2 length of projection, basal 1/3 broad. Valva with dorsal margin slightly convex, ventral margin sinuated, apex narrowly rounded; costa narrow; dorsal sella membranous with several setae, nearly rectangular; ventral sella with short, finger-shaped, and weakly sclerotised process; dorso-distal sella bearing a hook-shaped, strongly sclerotised process, basal broad with two small spins; sacculus broad. Juxta with basal part narrow, two arms long and slender, pointed apically. Phallus short, distal part with a long and pointed spine, slightly curved, as long as the length of phallus.
Distribution. China (Guangdong, Guizhou, Yunnan), India. Diagnosis. Externally, Loxoneptera triangularis resembles L. carnealis in the wing shape, but can be distinguish by the smaller wings, and costal and posterior areas of hindwing dark brown. In the male genitalia, it can be differentiated by the process on the dorso-distal sella with a strongly sclerotised stick, distal part of juxta with a strongly sclerotised and narrowly triangular process, and distal phallus with a relatively short and hook-shaped spine.

Loxoneptera triangularis
Description. Head. Frons pale yellow, with white lateral bands, basal white bands mixed with reddish brown scales. Vertex pale yellow. Labial palpus reddish brown, ventral side with white scales. Maxillary palpus reddish brown, broadened distally with scales. Antennae yellowish brown. Thorax. Dorsal side, patagia and tegula yellowish brown, mixed with reddish brown scales, ventral side grey white. Legs pale yellow. Wings. Wingspan 23.0-25.0 mm. Forewing pale yellow, termen dark brown, as well as from costal margin to posterior margin of cell, apex mixed with reddish brown scales; orbicular stigma weak, appearing as a dark brown point, reniform stigma black-brown and weak; fringe dark brown. Underside of forewing black from costal margin to posterior margin of cell. Hindwing pale yellow between CuA 2 and M 2 , remainders dark brown, without pattern, fringe yellow brown. Abdomen. Dorsal side of abdomen pale brown, ventral side grey white; sternite VIII in male slightly sclerotised with two stout anterolateral processes.
Male genitalia (Fig. 19). Uncus long and slender, distally narrowly rounded, with few hair-like setae. Saccus rounded. Dorsal projection of transtilla relatively slender and slightly curved, approximately as long as length of costa, distally bearing hair ~ 1/4 length of projection, basal 1/3 broad. Valva with dorsal margin slightly convex, ventral margin sinuated, apex narrowly rounded; costa slightly curved; dorsal sella membranous, with several setae, ventral sella with a small, hook-shaped and sclerotised process, narrow and pointed apically; dorso-distal sella with a long, stick-like, strongly sclerotised process, broad at terminal part, then pointed at apex; sacculus broad. Juxta shield-shaped, strongly sclerotised, distal part broad, with a strongly sclerotised and narrowly triangular process. Phallus long, distal end with a long and hook-shaped spine, narrow and pointed apically.

Distribution. China (Yunnan).
Etymology. The specific name derived from the Latin triangularis, referring to the triangular process in the end of juxta. Diagnosis. Loxoneptera rectacerosa resembles L. medialis in wing pattern, but the forewing of L. rectacerosa is brown from the costal margin to posterior margin of the cell, and white on costal margin, whereas it is pale yellow in L. medialis. In the male genitalia, dorsal margin of valva of L. rectacerosa makes a turn in the end, forming a distinct obtuse subapical angle; the process of the dorso-distal sella is smaller and shorter than that of L. medialis; distal end of phallus has a small and triangular sclerite, vesica is just with a group of spines.

Loxoneptera rectacerosa
Description. Head. Frons pale yellow, with white lateral bands. Vertex pale yellow. Labial palpus brown, with white scales on ventral side. Maxillary palpus brown, broadened distally with scales. Antennae yellowish brown. Thorax. Dorsal side, patagia and tegula yellowish brown, ventral side grey white. Legs white to yellowish white. Wings. Wingspan 29.0 mm. Forewing brown, mixed with reddish brown scales, costal margin white, posterior area pale yellow; orbicular stigma weak, appearing as a dark brown point, reniform stigma absent; fringe black-brown. Hindwing pale yellow, without any spot, apex mixed with a few pale brown scales. Underside of forewing black on cell. Abdomen. Dorsal side of abdomen pale brown, ventral side grey white; sternite VIII in male slightly sclerotised with two stout anterolateral processes.
Male genitalia (Fig. 20). Uncus long and slender, distally narrowly rounded, with few hair-like setae. Saccus rounded. Dorsal projection of transtilla relatively slender and slightly curved, ~ as long as length of costa, distally bearing hair ~ 1/4 length of projection, basal 1/3 broad. Valva with dorsal margin slightly convex, ventral margin sinuated, apex slightly pointed; costa straight, and making a turn on 1/5 of the end, forming a break angle on dorsal margin of valva subapically; dorsal sella membranous, with several setae; ventral sella with a hook-shaped and strongly sclerotised process, narrow and pointed apically; dorso-distal sella with a short and weakly sclerotised process; sacculus broad. Juxta with basal part narrow, two arms long and slender, pointed apically. Phallus long and slightly curved, distal end with a semi-circular sclerite, vesica with a group of short, straight, spine-shaped cornuti.
Female genitalia. Unknown. Distribution. China (Yunnan). Etymology. The specific name derived from the Latin rect-(straight) and arcerosus (spine-shaped), referring to the shape of cornuti in phallus. (Caradja, 1925) Diagnosis. The wing shape of Loxoneptera medialis is similar to L. rectacerosa but can be distinguished by the light yellow forewing and costal margin. In the male genitalia, it can be distinguished by longer spinous process on dorso-distal sella, distal end of phallus with a small and pointed spine, and vesica with two groups of short, spineshaped cornuti.

Loxoneptera medialis
Redescription. Head. Frons pale yellow, with white lateral bands. Vertex pale yellow. Labial palpus pale yellow, with white scales on ventral side. Maxillary palpus pale yellow, mixed with white scales, broadened distally with scales. Antennae yellowish brown. Thorax. Dorsal side, patagia and tegula yellowish brown, ventral side grey white. Legs yellowish white. Wings. Wingspan 25.0-30.0 mm. Forewing pale yellow, costal and terminal areas reddish brown; orbicular stigma weak, dark brown, reniform stigma weak, black-brown, appearing as a thick line on discocellulars; a weak, dark-brown stripe appearing between M 2 and CuA 1 ; fringe black-brown. Hindwing pale yellow, termen mixed with brown scales, without pattern. Underside of forewing pale yellow, without any spot. Abdomen. Dorsal side of abdomen black-brown, ventral side grey white; sternite VIII in male slightly sclerotised with bifurcate anterolateral processes.
Male genitalia (Fig. 21). Uncus long and slender, distally narrowly rounded, with few hair-like setae. Saccus rounded. Dorsal projection of transtilla relatively slender and slightly curved, approximately as long as length of costa, distally bearing hair ~ 1/3 length of projection, basal 1/3 broad. Valva with dorsal margin slightly convex, ventral margin sinuated, apex slightly pointed; costa slightly curved; dorsal sella appearing as a broad, slightly curved and stick-like sclerite, with several setae; ventral sella sclerotised, with a long, straight and stick-like process, narrow and pointed apically, apex slightly curved; dorso-distal sella with a pointed, hook-like, and strongly sclerotised process, as long as the process on ventral sella. Sacculus broad. Juxta with basal part narrow, two arms long and slender, pointed apically. Phallus short, basal 1/2 broad, distal end with a small pointed spine, and vesica with two groups of short, spine-shaped cornuti.
Distribution. China (Guangdong, Hainan). ( Diagnosis. Wingspan 28.0 mm. Loxoneptera pentasaris is best distinguished from other Loxoneptera species by greyish ochreous forewing with a white costal band, and without pattern. In the male genitalia, this species is similar to L. medialis in the shape of dorsal projection of transtilla, ventral sella and valva, but can be distinguished by the triangular dorsal sella, process of dorso-distal sella extending ventrad, distal margin of phallus densely decorated with short spines.

Figs 11, 23
Calamochrous bipunctalis Hampson, 1912 Diagnosis. Wingspan 34.0 mm. In appearance, Loxoneptera bipunctalis is best distinguished from other Loxoneptera species by pale ochreous yellow forewing, two blackish orbicular stigmata, and interrupted postmedial line of forewing. In the male genitalia, this species is similar to L. brevipalpis and L. dichroma but can be distinguished by the longer process of dorso-distal sella and the weakly sclerotised, sliceshaped cornutus of phallus.
Distribution. India. (Snellen, 1890) Diagnosis. Wingspan 33.0 mm. This species is distinguished by dull luteous forewing suffused with ochreous scales and bearing indistinct orbicular and reniform stigmata, lustrous hindwing suffused with grey scales along the costa. In the male genitalia, this species is similar to L. dichroma in the shape of the dorsal projection of the transtilla, ventral sella and valva, as well as by the process of dorso-distal sella extended  ventrad and beyond the ventral margin of valva. Loxoneptera brevipalpis can be distinguished by the thick and heavily sclerotised process of dorso-distal sella, and the heavily sclerotised, spiny, thumb-shaped cornutus.

Loxoneptera brevipalpis
Distribution. India (Sikkim). ( Diagnosis. Wingspan 34.0 mm. This species can be distinguished by having a brown stripe along posterior margin of the discal cell in forewing, and ventral-distal wall of phallus is weakly sclerotised and obliquely extended into a process.